A student in your study group prepared the following reformulated income statement for the Coca-Cola Company for 2007 (in millions):

Sales ................... $28,857

Cost of sales ............... 10,406

Gross margin ................ 18,451

Advertising expenses ............ 2,800

General and administrative expenses ...... 8,145

Other operating expenses (net) ........... 81

Operating income from sales (before tax) ..... 7,425

Tax ..................... 1,972

Operating income from sales (after tax) ...... 5,453

Equity income from bottling subsidiaries (after tax) . 668

Operating income .............. 6,121

Net financial expense (after tax) .......... 140

Earnings ................... 5,981

Summary balance sheets for 2007 and 2006 (in millions) were also prepared:

You point out that the income statement fails to identify core operating income from sales. Identify core operating income from sales (after tax) and then make the following calculations. Use average balance sheet amounts in denominators where applicable.
a. Core profit margin from sales
b. Core profit margin
c. Core return on net operatingassets(RNOA)

2007 2006 Net operating assets Net financial obligations $26,858 5.114 Common shareholders' equity 21,744 $18,952 2,032 $16,920